Halifax Water looks to biosolids for power6/8/2012
Halifax Water hopes to start powering part of its operation by burning biosolids and selling the rest of the energy to Nova Scotia Power.
The utility processes tonnes of treated human and organic waste into fertilizer at its subsidiary, N-Viro System Canada, at a plant near the Halifax airport’s business park.
It has proposed an $11-million expansion to that plant so it could turn biosolids into fuel, which could power that building and cut some of the utility’s dependency on natural gas. And $800,000 worth of energy would be sold to Nova Scotia Power each year, according to Halifax Water’s calculations.
The plant could process 120,000 tonnes of biosolids a year and produce enough energy to power about 2,200 homes, Jeff Knapp told the city’s environment and sustainability committee Thursday.
But first, the water commission must persuade the provincial Energy Department to recognize biosolids as a type of biomass, a renewable power source under its community feed-in tariff.
Beyond the province’s approval for the tariff program, the utility also needs the green light from the provincial Utility and Review Board, the water commission’s board and an environmental assessment.
The sludge would be mixed with wood chips and other biomass. It would produce about half the energy of coal, according to the utility.
Coun. Dawn Sloane (Halifax Downtown) welcomed the idea.
“Many of my constituents have been saying ‘Why don’t we burn it, (considering) the price of oil and gas and electricity now?’” she said.
But biosolids have had a contentious past in Halifax, with council flip-flopping about whether to use the substance as fertilizer on city property.
The issue arose in 2010 after the city used the fertilizer on vegetation along Dunbrack Street. Area residents started complaining about an offensive odour and said they had bouts of nausea.
A Halifax Water spokesman said Thursday that odour was traced to separating organics and not biosolids.
(The Chronicle Herald)